Gel composition for filling a breast milk duct prior to surgical excision of the duct or other breast tissue

ABSTRACT

The invention is a gel composition for delivery to a breast milk duct prior to surgical excision of breast tissue including cancerous lesions. The invention also provides methods of mapping all or nearly all of a breast milk duct prior to surgical excision of breast tissue, and method of identifying part or all of a breast duct or ducts as a surgical aide to a breast surgeon. Kits to support these methods and including these compositions are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/590,517,filed Jun. 9, 2000, which claims priority under 35 U.S.C. § 119(e) toProvisional Application No. 60/138,693, filed Jun. 11, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of this invention is gel compositions for delivery to a breastmilk duct for mapping a duct or ducts before surgical excision of anypart of the breast or ductal system.

2. Description of the Background Art

Breast cancer is the most common cancer in women, with well over 100,000new cases being diagnosed each year (see e.g. Goodson W H & King E B,Chapter 4: Discharges and Secretions of the Nipple, The Breast:Comprehensive Management of Benign and Malignant Diseases 2nd Ed. vol 2,Bland & Kirby eds. W.B. Saunders Co, Philadelphia, Pa. pp. 51-74,(1998)). Breast cancer usually arises from a single ductal system andexists in a precancerous state for a number of years. Surgicalprocedures can include removal of part or all of a duct containing acancerous lesion (a ductectomy), removal of a lump in a breast duct (alumpectomy), or performing a partial or total mastectomy. Theseprocedures would be well served with surgical adjuvants to aid thepractitioner to identify the duct or ducts or part of the duct to beremoved. For a complete description of such procedures on the breast,and definitions of the various types of breast tissue removalprocedures, see Love, S. THE BREAST BOOK, 2nd Ed. Lindsey Ed. PerseusBooks, Reading Mass. 1995.

Lumpectomies, ductectomies (partial or complete) and mastectomies(partial or complete) are successful only to the extent that allcancerous tissue is removed during the surgical procedure. Since breastcancer originates in a breast duct or ducts, identifying the duct orducts affected for surgery can provide a surgeon with a well needed,previously unavailable tool with which to generate clean margins at theexcision, increase the likelihood of getting all the cancer with theexcision, and increase long term likelihood of success from theprocedure. The present invention provides such benefits to breast cancerpatients and practitioners in the field.

3. Relevant Literature

Preoperative galactography (the injection of liquid dye into breastducts) has been used to target a lesion in a breast duct before surgicalexcision of the breast duct, as described in Van Zee et al., Cancer 199882:1874-80, Hou et al., Clin Imaging 1998 22:89-94, Vega et al., ActaRadiologica 1997 38:240-2, Hou et al., Radiology 1995 195:568-9, Bakeret al., AJR Am J Reontgenol 1994 162:821-4, and Grillo et al., AnnChirBynaecol 1990 79:6-9.

A process for forming an ablative or protective corneal shield or maskusing an in situ forming gel applied to the eye are described andclaimed in U.S. Pat. No. 5,587,175 to MDV Technologies for use inophthalmic laser surgery and drug delivery to the eye.

Biodegradable in situ forming implants and methods of producing them aredescribed in U.S. Pat. No. 5,733,950 to Atrix Pharmaceuticals using awater insoluble biodegradable polymer dissolved in a water solubleorganic solvent for the purpose of drug delivery to a site in the bodyincluding the mouth, periodontal pocket, the eye or the vagina wherethere is considerable fluid flow.

SUMMARY OF THE INVENTION

The invention provides a biocompatable composition comprising a polymerthat has a solubility greater than 0.5 grams per 100 ml of solvent, amolecular weight in a range of between about 1 and 500 kilodaltons and aweight/weight ratio of polymer to solvent in a range between about0.5:100 to 100:0.5; the composition is liquid in a solvent and undergoesa gel transition inside a target breast milk duct within about 30minutes of delivery of the composition to the target duct. The geltransition time can be in a range from about 0 to 2 minutes, from about2 to 5 minutes, from about 6 to 10 minutes, from about 11 to 15 minutes,from about 16 to 20 minutes, from about 21 to 25 minutes, or from about26 to 30 minutes. The solvent can be water.

The polymer can be alkyl celluloses, hydroxyalky methylcelluloses,hyaluronic acid, sodium chondroitin sulfate, polyacrylic acid,polyacrylamide, polycyanolacrylates, methyl methacrylate polymers,2-hydroxyethyl methacrylate polymers, cyclodextrin, polydextrose,dextran, gelatin, polygalacturonic acid, polyvinyl alcohol, polyvinylpyrrolidone, polyalkylene glycols, or polyethylene oxide. The solventcan be an organic solvent. The polymer can be water-soluble and comprisea polyethylenepolypropylene glycol block copolymer.

The gel transition can occur as a result of in situ cross-linking of thegel composition. The gel composition can comprise cross linkable freeradicals, or cationic/anionic cross linkable moieties. The cross linkingreaction can be activated by a chemical reaction, a change intemperature, or application of energy. The cross linking can beactivated by an application of an energy source selected from the groupconsisting of radiation, magnetic, ultrasonic, ultra-violet, radiofrequency, visible light, and heat.

The composition can undergo a gel transition between about 28° and 41°C. The composition can undergo a gel transition at the physiological pHof a breast milk duct. The pH can be in a range of from about pH 7.5 toabout pH 9.0, or in a range of from about pH 7.8 to about pH 8.2. Thecomposition can undergo a gel transition under isotonic conditions.

The gel in the target duct can be distinguishable from tissue. The gelin the target duct can be colored. The gel in the target duct can beharder than tissue. The gel can further comprise an additive to providedetection of the gel inside the target duct. Additionally, an additivemay be placed in the gel in order to provide detection of the gel beforeincision through the breast tissue and skin. The additive can be a dye.

The additive to distinguish the target duct from tissue can be a dyecapable of staining ductile tissue with a color visible to the nakedeye, a fluorescent dye, a radiographic contrast agent, a radionuclide, aferromagnetic material, a sonographically reflective material, athermographically reflective material, an impedance altering molecule, aradioactive agent, a vital dye or an agent detectable by infraredsensor. The additive can be a food coloring dye. The dye can beisosulfan blue, methylene blue, Chicago sky blue, marina blue,tetramethylrhodamine, Texas red-X, or Oregon green. The dye can be afluorescent dye including, e.g. fluorescein, rhodamine, or indocyaninegreen. The composition can comprise a therapeutic additive or adiagnostic additive.

The invention further provides a method for forming a in vivo gel map ofa breast duct comprising administering to a target breast milk duct abiocompatable composition comprising a polymer in a solvent capable of agel transition inside the target duct, wherein the composition is liquidat room temperature and undergoes a gel transition inside the targetduct within about 30 minutes of delivery of the composition. The methodcan further comprise cooling any one or more of the target breast, abreast duct access tool, the composition, and the polymer beforeadministering the composition to the target duct. The gel transitiontime can be in a range from about 0 to 2 minutes, from about 2 to 5minutes, from about 6 to 10 minutes, from about 11 to 15 minutes, fromabout 16 to 20 minutes, from about 21 to 25 minutes, or from about 26 to30 minutes. The composition can be administered using a catheter with alumen small enough to access a breast milk duct. The lumen of theportion of the catheter that accesses the breast duct comprises adiameter less than 0.10 inches. The composition can further comprisediagnostic or therapeutic additives or additives that aid in detectingthe duct.

The invention is a method for identifying one or more breast ducts in abreast or for identifying part of a breast duct for providing a surgeonguidance in a procedure to remove some or all breast tissue from thepatient comprising administering to one or more breast ducts in thetarget breast a biocompatable composition capable of a gel transitioninside a breast duct, wherein the presence of the gel inside the ductprovides identification of the duct during surgery. The procedure can befor example, a lumpectomy, a partial ductectomy, a total ductectomy, apartial mastectomy, or a total mastectomy.

The invention also provides a kit for mapping a breast milk duct with anin vivo gel comprising a biocompatable composition that is liquid atroom temperature and undergoes a gel transition in a breast duct withinabout 30 minutes of delivery to the target duct, a ductal access toolfor delivery of the composition having an access lumen small enough toaccess a breast milk duct, a container for the kit contents andinstructions for use of the kit. The gel transition time can be in arange from about 0 to 2 minutes, from about 2 to 5 minutes, from about 6to 10 minutes, from about 11 to 15 minutes, from about 16 to 20 minutes,from about 21 to 25 minutes, or from about 26 to 30 minutes.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The following preferred embodiments and examples are offered by way ofillustration and not by way of limitation.

The invention provides a biocompatable composition comprising a polymer.The composition is useful for partially or completely filling a breastduct with the composition to aide in the surgical excision of a lump inthe duct, a part of the duct, the entire duct, a partial mastectomy, ora complete mastectomy. For the composition to be biocompatable, allparts of the composition are biocompatable, thus including the polymer,the solvent and the resulting gel after a gel transition. Any additivesmust be biocompatable as well. Biocompatability is generally establishedby government regulatory standards. Compounds that have not been testedagainst government standards may none the less be biocompatable if theycan be tested and approved for use in an animal or human. Thebiocompatable composition should also be nontoxic, including also thatthe polymer, solvent, resulting gel and any additives are also nontoxic.

The polymer can be soluble in any solvent, aqueous, organic, non-organicor other solvent, provided the solvent is biocompatable and non-toxicfor humans. For the purposes of this invention, the polymer is injectedinto the ductal lumen and after gelation of the polymer in the duct, theduct is removed by surgical excision. Therefore, the polymer can beoptionally biodegradable, although it is not an absolute requirementbecause most if not all of the gelled polymer is removed upon surgicalexcision of the breast duct. Where, however, it is anticipated thatsmall amounts of the polymer or gel composition remain behind after suchsurgical excision, it would be advantageous to the procedure to knowthat the gel composition left behind will biodegrade within the bodywithin a reasonable period of time.

The solubility of the polymer in the solvent should be greater than 0.5grams per 100 ml of solvent, and thus the polymer in solution can havesolubility in a range from about 0.5 grams in 100 ml to, for example, anupper limit of 1 gram per ml. It is understood that the solubility willvary considerably with the addition, or absence of additives, thechemical relationship of the solvent and polymer to each other and otherfactors (e.g. such as temperature, pH, ion content or concentration,additives, etc.) that affect the gel transition of the polymer in thatsolvent.

The molecular weight of the polymer molecule should be in a range fromabout 1 kilodalton to about 500 kilodaltons, thus including such rangesas about 5 kD to about 450 kD, about 10 kD to about 400 kD, about 25 kDto about 350 kD, about 50 kD to about 250 kD, about 75 kD to about 200kD, and about 100 kD to about 150 kD.

The weight/weight ratio of the polymer to solvent should be in a rangebetween about 0.5:100 to 100:0.5, thus including any such wt/wt ratiosof polymer to solvent between a polymer weight of between 0.5 and 100and a solvent weight of between 100 and 0.5. For example, the polymerweight could be 10 and the solvent weight could be 80, the polymer couldbe 0.8 and the solvent could be 20, the polymer could be 20 and thesolvent could be 10, and so on.

The polymer can be any suitable polymer fitting the specificationslisted. Thus, the polymer can include many of the presently known,developed, or otherwise available polymers, copolymers, terpolymers orother polymer-like entities capable of forming a gel under the rightconditions for that polymer or polymer composition. For example, anybiocompatable polymer listed in THE MERCK INDEX, 12th ed. 1996,Whitehouse Station, N.J. which meets the requirements of the compositionas stated can be used.

Some exemplary polymers and the like are disclosed or described in thefollowing publications including, e.g. U.S. Pat. Nos. 5,733,950,5,739,176, 5,324,519, 5,856,367, 5,702,716, 681,873, 607,686, 5,599,552,5,502,092, 5,340,849, 5,278,202, 5,717,030, 5,707,647 and 5,278,201 toAtrix Pharmaceuticals of Fort Collins, Colo.; a product called BioGlue™produced by CryoLife located at Atlanta, Ga.; cyanoacrylates asdescribed in Trott, J, JAMA 1997 277: 1559-1560; U.S. Pat. Nos.5,874,500, 5,800,541, 5,783,178, 5,744,545, and 5,739,208 to eitherCohesion. Technologies of Palo Alto, Calif. or Shearwater Polymers, Inc.of Huntsville, Ala.; U.S. Pat. No. 5,856,367 to Minnesota Mining andManufacturing Co. of St. Paul Minn.; U.S. Pat. No. 5,206,341 to SouthernResearch Institute of Birmingham, Ala.; U.S. Pat. Nos. 5,847,023,5,593,683 and 5,587,175 to MDV Technologies, Inc. of San Diego, Calif.and FloGel™ product provided by MDV technologies; U.S. Pat. Nos.5,709,854, and 5,716,404 to Mass. Inst. Tech of Cambridge, Mass.; U.S.Pat. No. 5,630,015 to Ethicon, Inc. of Somerville, N.J.; U.S. Pat. No.5,861,174 to University Technology Corp.; U.S. Pat. Nos. 4,100,271 and4,188,373 to Cooper Laboratories, Inc.; U.S. Pat. No. 5,836,970 to theKendall Company of Mansfield, Mass.; U.S. Pat. No. 5,660,854 to Hayneset al.; U.S. Pat. No. 4,619,913 to Matrix Pharmaceuticals of Menlo Park,Calif.; WO 97/05185 and WO 96/11671 to Focal Inc. of Lexington, Mass.;WO 97/00275 and WO 96/02276 to Gel Sciences, Inc. of Bedford, Mass.; WO97/22371 and U.S. Pat. No. 5,475,052 to Collagen Corp. of Palo Alto,Calif.; WO 97/15242 to Seare; WO 96/31547 to Ciba-Geigy; U.S. Pat. No.5,861,174 to University Technology Corp. of Boulder, Colo.; and U.S.Pat. No. 5,827,835 to Alcon Laboratories of Fort Worth, Tex.

Although the polymer can be any polymer that meets the functionalrequirements of delivery to a breast duct as described, and compositionrequirements as stated, the composition can comprise a polymer selectedfrom the group consisting of alkyl celluloses, hydroxyalky methylcelluloses, hyaluronic acid, sodium chondroitin sulfate, polyacrylicacid, polyacrylamide, polycyanolacrylates, methyl methacrylate polymers,2-hydroxyethyl methacrylate polymers, cyclodextrin, polydextrose,dextran, gelatin, polygalacturonic acid, polyvinyl alcohol, polyvinylpyrrolidone, polyalkylene glycols, and polyethylene oxide. In addition,the polymer can be water-soluble and comprise apolyethylenepolypropylene glycol block copolymer (see entry number 7722Poloxamers page 1303, THE MERCK INDEX, 12th ed. 1996, WhitehouseStation, N.J.).

The gel transition of the gel composition in the duct can occur as aresult of in situ cross linking of the gel composition. Such a crosslinkable gel composition can comprise cross linkable free radicals, orcationic/anionic cross linkable moieties. For example, the gelcomposition can comprise cyanoacrylates, or FocalGel™. The cross linkingreaction can be activated by a chemical reaction, a change intemperature, or the application of energy. The energy source can belight. Indeed, the cross linking can be activated by an application ofan energy source selected from the group consisting of radiation,magnetic, ultrasonic, ultra-violet, radio frequency, visible light, andheat. These energy sources can be applied to the polymer or compositionjust prior to administration in the duct, or can be applied to thebreast during or just after the composition is administered to thetarget duct. The energy sources are derived from standard sources forthe energy applied.

The biocompatable composition is liquid before delivery to a breast ductand undergoes a gel transition inside a target breast duct within about30 minutes of delivery of the composition to the target duct. The geltransition time can be in a range from about 0 to 2 minutes, from about2 to 5 minutes, from about 6 to 10 minutes, from about 11 to 15 minutes,from about 16 to 20 minutes, from about 21 to 25 minutes, or from about26 to 30 minutes. The gel may begin to transition slowly, so that a fewseconds after the polymer has been exposed to a condition which beginsthe gelling process, the gelling process can begin, but gelling may notbe completed right away. Delivery may be facilitated using the polymerin a liquid form, or a slightly viscous form (i.e., when the gelling isbeginning to take place). The gel transition can also begin as soon asabout a minute after delivery of the first amount of gel composition tothe duct. Preferably the gel transition will not begin until theearliest delivered aliquot of the gel composition has been delivered toand infused to a distal region of the ductal architecture.Alternatively, where delivery is facilitated using a slightly or mildlyviscous polymer, the gel transition is beginning sooner than before allor part is delivered to the duct, but the polymer is still of asufficient consistency that delivery to the duct can be accomplished.Thus, it is preferable that the gel composition undergoes a geltransition after the first-delivered amounts of the composition have hadtime to infuse through the ductal lumen. A gel composition that gels toosoon too completely may block infusion of later-delivered portions ofthe composition and the duct will not be entirely filled with the gel.The time needed to have the gel composition remain liquid and infusethrough the duct will vary depending on such parameters, for example, asthe flow rate of the gel composition, the speed of gelation once the geltransition begins, the cause of the gel transition, the depth ofpenetration of the delivery tool into the catheter, the lumen size ofthe delivery tool, and the proficiency of the practitioner deliveringthe gel.

The challenge of delivery of a liquid polymer to a breast duct for a geltransition inside the duct is characterized by among other restrictionsthe narrowness of the ductal lumen, and the smallness of the ductalorifice that leads from the nipple surface into the duct, and theextensive relative length of the ductal lumen and the tributary lumensof the ductal architecture that feed into the main lumen. With regard tothe ductal orifice size, a catheter having an access tip less than orequal to 0.10 inches may access some of the larger orifices; for smallerorifices catheter tips of 0.050 inches or less are required, and someductal orifices can only be accessed with tips less than 0.025 inches,and other orifices of the smaller ducts may required an even smallercatheter or entry device lumen, e.g. in the range of from 0.024 to 0.010inches. Additional challenges include delivering the polymer in liquidform before it gels, and then providing a formulation adapted to conformto a gelation time that appropriates enough time to deliver the gel andwhich also gels sufficiently quickly to provide a gel structure insidethe ductal architecture to identify the duct for excision or othermanipulation.

A polymer and solvent mixture (with or without additives that affectgelation, etc.) must be tested for the ability to be delivered to abreast duct in a specific device (i.e. one selected for the procedure)having a certain lumen size, especially where smaller lumen sizes mightnecessitate such changes in the parameters of the gel composition thatfacilitate a later gel transition, and higher flow rate of the liquidbefore gel transition. Delivering the gel composition to suitable animalor other tissue models can test whether a gel composition fits into theparameters required of the composition. Thus, for example, the gelcomposition can be delivered to rabbit pelts having nipples, pig peltshaving nipples, nipples of live rabbits, nipples of live pigs, ducts ofmastected human breasts, etc. A simple preliminary non-animal test canbe conducted using the gel composition delivered in a catheter to awater bath at an adjusted and appropriate temperature (e.g. at aboutbody temperature or about 37° C.), or the water can be adjusted withother parameters that would be key to the gel transition, for exampleion content or pH. Also the bath could be exposed to an activationsource, for example a light source in the case where the gel cross linksin the presence of visible or other light, as the gel is delivered, orthe gel could be delivered to a duct-like tube (e.g. a latex glovefinger) resting in the water bath, in order to simulate delivery of thecomposition to an environment similar to a breast duct either during orprior to activation. Compositions that gel in the bath and not in thecatheter would be considered excellent candidates for further tests inanimal and human breast milk ducts. See Sukumar et al., (Animal modelsfor breast cancer), Mutation Research. 333(1-2):37-44, 1995 for otherexamples of suitable animal models for further testing.

Aside from issues of lumen size of the device for delivery of the gelcomposition to a human breast duct, the device for delivery of thepolymer should also be forgiving of breast tissue, and not prone topenetrating or breaking a lumen wall, and not prone to injuring thebreast or ductal lumen in any way. Catheters are excellent deliverytools for this purpose because they are not sharp and thus have areduced risk of rupturing a ductal wall, or nicking tissue. Otherdelivery devices may also be used, including, e.g. cannulas, needles,other lumens or tubes, especially when these devices are made withforgiving materials and have a forgiving design capable of penetrating aductal lumen without violating the tissue walls of the lumen.

The delivery tool may penetrate into the ductal lumen as far asnecessary for successful delivery of the gel composition. Generally thisdistance can be in the range from about 1 millimeter to about 5centimeters, or if practical and necessary, into a location at or beyondthe lactiferous sinus. However, it may be the case that a small amountof penetration, e.g. 2 cm may be enough to deliver the liquid gelcomposition, allowing that the liquid will infuse into the duct on itsown once delivered in the top most portion of the ductal lumen. It isanticipated that delivery of the gel composition might begin with arelatively deep insertion of the delivery tool into the ductal lumen,and a subsequent gradual withdrawal of the delivery tool as the liquidis delivered and infused into the duct, and especially as the gelcomposition begins a gel transition.

A syringe or other infusion device may directly infuse the liquid intothe duct, or if attached to the delivery tool, a syringe may infuse theliquid into a delivery lumen of the tool. Delivery of the composition toa breast duct is preferably done by entering the ductal orifice.Preferably during delivery the ductal wall remains intact and the gelmaterial remains within the ductal architecture. The gel composition isinjected into the breast duct where it infuses through the ductalarchitecture that connects with the ductal orifice that was injected. Anappropriate preparation for a temperature sensitive polymer in order toprovide an appropriate window for administration of the gel and toensure gelation once inside the duct (and not before) may be cooling theliquid polymer to a temperature below gelation temperature. For example,the polymer may be cooled before it is administered by being placed onice, or refrigerated. In addition, an administration tool may be cooled,and/or the breast itself may be placed on ice or wrapped in a coolingcloth that lowers the skin temperature. Once administered, the bodyprovides a source of warming and thus allows for gelation. Othermeasures may be taken for polymers that are not temperature sensitivebut which respond to other changes that can be controlled just prior toadministration in order to maximize the opportunity for the polymer topenetrate the ductal architecture before gelation occurs. As the liquidpolymer is infused into the breast duct, application of externalpressure (including e.g. massaging the breast) may be used to encouragea mixing of the liquid with the ductal contents (including ductalfluid), and a diffusion or continued infusion of the liquid into thedistal areas of the ductal architecture before substantial geltransition occurs.

The goal of the infusion of liquid polymer is to have the gelcomposition enter the duct as a liquid and fill the entire duct,including, e.g. the lactiferous sinus, the distal regions of the ductalarchitecture, and the main lumen of the duct. The liquid polymer must beable to enter the duct and infuse within the duct before it gels (i.e.undergoes a gel transition). Thus, since it takes a period of timebefore the liquid has diffused into all regions of the breast duct, orat least the main lumen of the breast duct, the polymer should notundergo a gel transition until it has been substantially infused into atleast the lower (most distant) regions of the main ductal lumen. At thepoint of substantial infusion into the lower regions of the main ductallumen, and after that where the polymer has filled most of the breastduct, the gel transition can most timely and beneficially occur.Alternatively, the gel can begin to transition early, but slowly, andcan complete its transition only after all of the gel or polymer isdelivered to the duct. Different gels may act differently with regard togelation starting time, rate of gelation, time it takes to gel, andfinal consistency achieved. Many combinations of attributes andqualities of different gel combinations can be worked with to achievethe ultimate goal of creating a map in the duct, and many combinationsmay be comparatively satisfactory for a given patient scenario.

If too much time passes before the gel transition occurs, the procedureruns the risk of having the solvent diffuse and/or the conditions insidethe duct and with the liquid polymer to change to a point that altersany optimal gel transition or the ultimate consistency of the gel. Inaddition, because the delivery of the gel composition to the breast ductis for the purpose of identifying and then excising the duct in surgery,an optimal time period before the gel transition is complete isapproximately a maximum of 30 minutes. Thirty minutes or less allows theanesthetic time to take effect, and the practitioner and assistants timeto prepare the surgical site for the procedure. Also, if too much timepasses before the gel transition, some of the additives may diffuse intothe lumen walls of the duct, and lose their effectiveness for whateverpurpose inside the ductal lumen. For example, where an additive is onethat can be detected in the gel, and is required to locate thegel-filled duct, if that additive has a chance to diffuse through thelumen wall and perhaps into surrounding tissue before gel transitionoccurs, the effectiveness of that additive is greatly reduced.

It is estimated that the optimal time period for a gel transitionoccurring when the liquid polymer is inside the duct is about 30 minutesor less, possibly in a range from about 1 to about 25 minutes, alsolikely in a range from about 5 to about 20 minutes, credibly in a rangefrom about 8 to about 17 minutes, and also in a range from about 10 toabout 15 minutes. Giving the liquid time to enter the duct, requires anapproximate 30 seconds to 5 minutes of infusion of the liquid polymerinto the duct, during which time the conditions inside the duct are notsufficient to induce a gel transition, and after which time the liquidcan be allowed to undergo a gel transition. The gel transition can bevirtually immediate, or may take minutes, i.e. up to about 30 minutesaltogether from the first moments of infusion of the liquid polymer.Preferably the composition does not begin a gel transition until afterit has substantially filled the breast duct, or at least until theearliest delivered portion of the composition has had the opportunity toseep to the deeper recesses of the duct.

Additionally, the gel can harden to various consistencies, provided itbecomes less liquid and more viscous once it undergoes a gel transition.Thus, the gel can be, for example, less hard than the surroundingtissue, about the same consistency as the surrounding ductal lumen,somewhat stiffer or harder than the ductal lumen and/or the surroundingbreast tissue, or much stiffer and harder than the ductal lumen and/orthe surrounding tissue. The main objective is to provide a gel-filledbreast duct that is easily identified in virtually its entirety, andwhich can be excised cleanly leaving clean margins, without rupturingthe duct, causing leakage of the gel or ductal contents, and thuscontaining in the excised material the whole of the sought-aftercarcinoma or other lesion. The gel hardness may also be considered inmore absolute and less comparative terms, so that an essentially viscousgel may work for the purposes of the invention and a much harder gel mayalso work. To give more or specific detail to hardness or texture ofgel, provided is a range of viscosities for various materials thatshould be sufficient for our hydrogel formulation. The solidifiedhydrogel can have a viscosity in the range of 1.004 centistokes to −55Mcentistokes which is similar to the consistency of water to molasses,respectively. For reference, viscosities of other liquids are: Tar 66Mcentistokes Honey 73.6 centistokes Glycerine 648 centistokes Food oil30-32 centistokes Fuel oil 2-15 centistokes

The polymer can undergo a gel transition based on a change of conditionsinside the breast duct. The conditions changed can be any condition thatcauses a gel transition for that polymer. Some exemplary and commonconditions include e.g. temperature change, pH change and ion change.For example, with regard to temperature, the gel composition can beliquid at temperatures below room temperature (i.e. at temperaturesbelow about 22° to about 27° C.) and can undergo a gel transition in therange of body temperature (i.e. at temperatures in a range from about35° C. to about 40° C.). In such a case using such temperature sensitivepolymers, the polymer can be liquid for example at refrigeratedtemperatures (i.e. about 2° C. to about 15° C.) and although deliveredto a breast duct at room temperature, can be kept on ice or refrigerateduntil moments before delivery, allowing thus only slight warming beforethe liquid is delivered to a breast duct. In addition, the delivery toolcan be chilled, and the breast can be cooled or wrapped in a cooling pador contacted with an ice laden water bottle or otherwise chilled orcooled, for example.

Some gel compositions will undergo a gel transition based on a pHchange, and thus gel compositions that are liquid at slightly basic oracidic conditions may transition when inside the breast duct having a pHin the range of physiological pH (i.e. in a pH range from about pH 7.2to about pH 9.2, more specifically in a pH range from about pH 7.5 andpH 9.0, and more specifically in a pH range from about pH 7.8 to aboutpH 8.2). Generally, body secretions tend to be buffered, and ductalfluid being a body secretion creates a buffered environment inside thebreast duct. Thus as a pH sensitive gel composition contacts thesomewhat buffered environment of a breast duct containing breast ductfluid it can undergo a gel transition. The pH sensitive composition willbe liquid at some non-physiological pH value (being either slightly moreacidic or slightly more basic than the physiological pH of a breast ductor breast duct secretions) and will undergo a gel transition inside abreast duct once it contacts the buffered environment of the duct.

Some gel compositions will undergo a gel transition based on ions in theduct. Thus, for example a gel composition that is liquid at hypotonic orhypertonic conditions can undergo a gel transition inside a breast ductthat is isotonic. Ionic conditions can be created relative to the ioniccondition of breast duct fluid by adding or removing ions relative tothe ionic content of ductal fluid from a breast. Such ions can include,e.g. Na+, Ca++, Cl−, Mg++, Zn++, Fe++, K+ and other ions that exist inthe body in some amounts or which are not harmful to the body. For anindication of the ion content of breast duct fluid see Petrakis et al.,“Nipple aspirate fluids in adult nonlactating women—lactose content,cationic Na+, K+, Na+/K+ ratio, and coloration”, Breast Cancer Research& Treatment. 13(1):71-8, 1989.

The biocompatable gel composition in the target duct after geltransition can be distinguishable from tissue, i.e. the surroundingtissue including the ductal lumen and the breast tissue or any cancerousor precancerous tissue in the breast duct. The composition that hasundergone its gel transition can be distinguishable by any factor thatcan distinguish it from tissue, or any number or combination of thesefactors. The gel might be colorless, for example, but hardened, and byhardening inside the duct, might make the gel and the duct it fillsdistinguishable from the surrounding breast tissue by virtue of thedifferent density and tensile strength of the gel versus the ductallumen and surrounding breast tissue. Thus, the stiffness of the ducthousing the gel alone can make the duct detectable to a practitioner.

Other mechanisms of making the gel inside the duct distinguishable fromtissue include having the gel contain a color different than thesurrounding tissue or ductal lumen, and which is visible to the nakedeye, or other wise visible with special light. For example, the gel canbe pink, green, blue, yellow, purple, or any other color available in abiocompatable dye that can be added to the gel composition beforedelivery to the duct. Other mechanisms of making the gel distinguishablefrom the tissue of the breast can include placing additives in the gelthat can be detected by nonvisual means. Such nonvisual means caninclude, e.g. detection by special sensors capable of sensing theparticular additive in the gel that is not present in the surroundingtissue. Thus, after the composition has been delivered to the duct andthe gel transition has occurred, a gel having such additives can be“read” and detected by using the sensor appropriate for the additive.Thus, for example, a practitioner can begin removal of the target ductand use the sensor to confirm that the right duct is being removed, andthat all portions of the target duct are being removed. Tissue that doesnot read positive with the sensor can be left behind in the breast.

Although it is possible that the biocompatable composition may have veryfew or no additives, and by virtue of hardening alone can be used todetect the breast duct for surgical excision, it is more likely that atleast one if not more than one other additives can be added to thecomposition to aid in the detection of the gel inside the target duct,and so provide for the detection of the target duct for surgicalexcision. The additive can provide visual detection of the gel by thenaked eye, or can be an additive that is capable of detection by aspecial sensor or machine or other mechanism that is sensitive to thepresence of such an additive and which can detect material that has theadditive and distinguish such material from other material notcontaining the particular additive. Thus, the additive can be, e.g. afood coloring dye, for example a red, blue, green or yellow foodcoloring dye. For example FD&C green #8, FD&C Blue #1, FD&C Blue #2,FD&C Green #3, FD&C Red #3, FD&C Red #40, FD&C Yellow #5, FD&C Yellow #6dyes may be used. The additive can also be another type of visuallydetectable dye including, e.g. isosulfan blue, methylene blue, Chicagosky blue, marina blue, tetramethylrhodamine, Texas red-X, or Oregongreen. The additive can be a fluorescent agent, including e.g. anycommercially available fluorescent agent that is biocompatable. Someexemplary fluorescent agents include, e.g. fluorescein, rhodamine orindocyanine green, but others also exist and may be available from suchcompanies as Molecular Probes located at Eugene, Oreg., or PromegaCorp., located at Madison, Wis., and other companies that supplyreagents for biomedical scientific research purposes. Other fluorescentdyes that may be adaptable to use in a gel in a breast duct includegreen fluorescent protein (GFP) or blue fluorescent protein (BFP).

The additive can also be an agent detectable by other nonvisual means,including, e.g. a radiographic contrast agent, a radionuclide, aferromagnetic material, a sonographically reflective material, athermographically reflective material, an impedance altering molecule, aradioactive agent, and an agent detectable by infrared sensor. An agentdetectable by infrared sensor is available from HotHands/Johnston SalesCo., Little Rock, Ark. (phone 501-661-1199). Such agents that are notvisually detectable require some kind of sensor or detector to detecttheir presence. The usefulness of the additives that are detectable bynonvisual means includes that once the duct is removed, the tissue canbe passed over with the sensor to determine if all portions of thegel-filled duct have been removed. Where some pieces of gel and/or ductand gel remain, these remnants can also be removed, providing anopportunity of leaving clean margins with little or no risk ofreoccurrence of the cancer or precancer that is removed with the ductalexcision.

In addition, the additive can be colored so that after delivery to thebreast duct it is visible through the skin to aid thepractitioner/surgeon to identify the duct externally, and so plan anappropriate location for the initial incision. Such additional qualityof a colored gel provides the opportunity to further limit the removalof healthy tissue. Thus the additive can comprise a dye detectable fromoutside the breast skin before the incision is made.

More than one additive can be used to make the gel-filled ductdetectable, each additive perhaps performing a slightly differentpurpose in the process. For example, an additive that makes the gelvisible to the naked eye or to the naked eye with the aide of a speciallight (e.g. UV light) can be used so that a practitioner can see at aglance where the duct filled with gel is and what kind of cuts need tobe made in and around the surrounding tissue to removed the gel-filledduct. However, another additive can also be added in order to detectminute particles of gel in small tributary regions of the duct and tocheck the tissue area after excision for whether the gel and duct havebeen completely removed. For example, an additive that can be detectedby a sensor, e.g. a radiographic contrast agent, or a radionuclide, canbe used and a sensor to detect the radiographic contrast agent or asensor to detect the radionuclide can be passed over the region ofexcision to check for complete removal of the target duct and anyremaining pieces of gel.

Additives can also be added to the gel composition in order tofacilitate specific and differential identification of lump or lesion ina duct. For example, additives that preferentially bind to tumor cellantigens, epitopes, receptors, or other markers could be added to thegel. Such identifiers of tumor or cancer cells could be visiblethemselves (either aided or unaided with light or other aides orsensors) or could require an additional coupling to a label in order tomake the additive identifiable to the practitioner seeking to excise thelump, lesion or other cancerous tissue. Antibodies are one type ofadditive that may be specific for a tumor cell marker and could also becoupled with a label (such as a florescent tag also provided in the gel)in order that the tumor cells can be visualized by the practitionerseeking to perform the excision. Other additives might include smallmolecules, antibody fragments, proteins or protein fragments specificfor receptors on the tumor cells, or additives that bind moleculesassociated with the presence of a tumor and which can serve as adequateindicators of the location of a lesion of tumor cells in the duct andthe environs of the duct and breast tissue surrounding the duct.

In addition to additives that aid in the detection of the gel in theduct, the composition can have other additives for other purposes. Forexample, the additive can be therapeutic to the ductal tissue andsurrounding tissue. A therapeutic additive can contact the tissue of theductal lumen and the surrounding breast tissue and act on the lumen orthe surrounding tissue, particularly on the tissue that remains behindafter the excision to aid in any number of functions including, e.g.healing the tissue from the excision, eliminating any remainingcancerous or precancerous cells in the duct or tissue, antibioticeffects to reduce the risk of infection in the remaining tissue, and anyother beneficial therapeutic effects that might be desired after theexcision. Thus, such additives can include, e.g. an anticancer oranti-proliferative agent, an antibiotic, or a wound-healing agent. Anyagent or drug deemed beneficial in locally treating the ductal tissue orsurrounding breast tissue during and after the excision of the duct canbe added to the gel. In some cases the therapeutic additive maypreferentially seep through the gel composition or gel matrix to theductal lumen and to the surrounding breast tissue to provide itstherapeutic benefit.

Agents or drugs that may be used as therapeutic additives for the gelcomposition include e.g. those discussed and presented in Harris et al.Ed. BREAST DISEASES, J. B. Lippincott Co., Philadelphia, Pa. 1991; Blandand Copeland Ed., THE BREAST, W. B. Saunders Co., Philadelphia, Pa.1991; and Love, S. THE BREAST BOOK, 2^(nd) Ed. Lindsey Ed. PerseusBooks, Reading Mass. 1995. In general any chemotherapeutic agent orhormone modulating agent may be used. For example, such modulators ofestrogen activity may provide some protective effect to the surroundingtissue including e.g. tamoxifen, raloxifene, EM 800, droloxifene,ioxdroxifene, RU 39411, RU 58668, ICI 164384, faslodex, soy, a soyisoflavone, a gonadotropin releasing hormone agonist, or an aromataseinhibitor. The soy isoflavone can be genistein or daidzein. Thearomatase inhibitor can be toremifene. Some possible candidate estrogenactivity modulators are described in el Khissiin and Leclercq, (1998)Steroids 63(11): 565-74; O'Regan et al. (1998) J Nat'l Cancer Inst90(20):1552-8; Favoni and Cupis (1998) Trends Pharmacol Sci 19(10):406-15; Williams, GM (1998) J Nat'l Cancer Inst 90:1671; Huynh et al.(1996) Clin Cancer Res 2:2037-2042; England and Jordan (1997) Oncol Res9:397-402; Ashby et al. (1997) Regul Toxicol Pharmacol 25:226-31, Longet al., (1998) J Steroid Biochem Mol Biol 67:293-304. In addition,estrogen activity modulators obtained from plants or foods can be used,including soy and soy isoflavones, including genistein and daidzein, asdescribed in Xu et al. (1998) Cancer Epidemiol Biomarkers Prev 7:1101-8,Charland et al. (1998) Int J Mol Med 2:225-228, Franke et al. (1998) AmJ Clin Nutr 68:1466 S-1473S, Kim et al. (1998) Am J Clin Nutr 68:1418S-1425S, Shao et al. (1998) Cancer Res 58:4851-7, Shao et al.,Journal of Cellular Biochemistry 69(1):44-54, 1998; Liggins et al.(1998) Anal Biochem 264:1-7, Kinoshita et al. (1998) Adv Exp Med Biol439: 1178-29, and Dees and Kennedy (1998) Curr Opin Oncol 10(6):517-522.Estrogen activity modulators that are aromatase inhibitors are describedin Mor et al. (1998) J Steroid Biochem Mol Biol 67(5-6):403-411; Goss etal. (1999) Oncology 56(2):114-121; Coombes (1998) Recent Results CancerRes 152:277-84; Costa et al. (1999) Cancer 85:100-3; Long et al. (1998)J Steroid Biochem Mol Biol 67(4): 293-304; and Lamb and Adkins (1998)Drugs 56(6):1125-40. Gonadotropin hormone releasing agonists (GNRHA) aredescribed at websitewww.amaassn.org/special/womh/newsline/reuters/03315440.htm (date4-5-99); and in other publications including Jonat (1998) Br J Cancer 78Suppl 4:5-8; Szarnel et al. (1998) Cancer Chemother Pharmacol42(3):241-6; Clardo et al. (1998) Minerva Ginecol 50(1-2):25-29; Nagy etal. (1996) Proc Natl Acad Sci USA 93(14):7269-73; Burger et al. (1996)Eur J Obstet Gynecol Reprod Biol 67(1):27-33.

Additives to the gel composition may also perform a diagnostic function.A diagnostic function may be particularly useful where a lesion isbelieved to be in the duct, but which has not been specifically locatedor specifically identified for cell type or by cytology or histology.For example, the gel composition can contain an additive that binds tocell surface proteins on the surfaces of ductal epithelial cells toidentify, e.g. abnormal cells. The diagnostic additive can bind solublefactors or molecules that would be detected in the ductal fluid. Thediagnostic additive can also be capable of passing through a cell walland be able to bind intracellular molecules or components. Thus, using adiagnostic additive, the gel-filled duct can be analyzed after excisionfor the character and contents of the cells and fluid in the duct and onthe walls of the lumen. Such analysis can be used subsequently to treatthe patient post-excision and/or to monitor the patient for anysubsequent occurrence in another breast duct. Preferably the diagnosticagent will be or will be capable of conjugation to a marker agent thatwill aid in identification of the agent in the duct. For example, thediagnostic agent may be an antibody capable of binding a cell surfacemarker on a carcinoma cell and will be conjugated to a fluorescentmarker that can be identified under fluorescent light. By identifyingthe location of the diagnostic antibody that preferentially binds thecarcinoma cells in the duct, for example, the location of the lesion orlesions in the duct can be identified post excision and/or during thesurgical removal of the duct. The cells of the lesion of the excisedduct may also be subsequently sampled and further analyzed.

Diagnostic analysis of an excised duct can include examining diagnosticmarkers in the gel to determine the presence of precancerous orcancerous ductal epithelial cells. The hardened gel in the removed ductcan be analyzed for the presence of soluble factors or other componentsthat might indicate the presence of cancerous or precancerous ductalepithelial cells in the duct. The epithelial cells in contact with ortrapped within the gel can be analyzed for protein markers, nucleic acidmarkers, chromosomal abnormalities, or other characteristic changes thatwould signal the presence of cancerous or precancerous cells. Inaddition, other cells found in the duct can also be analyzed, e.g. foran increase or decrease in these cells as compared to normal ductalfluid, or for qualities of these cells themselves. Thus, the ductcontaining the hardened gel can be analyzed e.g. for soluble proteincontent or presence of other ductal fluid components, including alsosecreted products of ductal epithelial cells) or the ductal epithelialcells themselves can be analyzed, for example, for cell morphology, forprotein markers, for nucleic acid markers, and for biochemical markers.In addition, any of the cells of the duct can be analyzed formorphological abnormalities in cell components, including, e.g.morphological abnormalities of the nucleus, cytoplasm, golgi apparatusor other parts of a cell. The cells can be analyzed for whether they door don't aggregate (e.g. in clumps) or by making comparisons of theductal epithelial cells with other cell types retrieved in the ductalfluid (e.g. macrophages, lymphocytes, foam cells and other possiblecomponents of ductal fluid). The ductal epithelial cells can be analyzedfor their relationship to other (e.g. neighboring or distant) ductalepithelial cells, to other cells in the lumen or surrounding the lumen,(including e.g. myoepithelial cells), and for the molecular contents orthe morphology of the ductal epithelial cells, including, e.g. proteinmarkers, nucleic acid markers, biochemical markers in the cells or onthe cell surfaces or for any evidence of neoplasia.

In addition to some markers discussed and/or articles or books cited onbreast cancer and breast precancer markers, including markers listed inPorter-Jordan and Lippman, “Overview of the biological markers of breastcancer”, Hematology/Oncology Clinics of North America vol. 8 (1):73-100,1994), the following cancer markers are listed here as exemplary and maybe used as well as other markers to analyze the condition of a breastduct, including analysis of the ductal contents (including fluid andcells) that are trapped in the hardened gel. Standard assay proceduresfor identifying the markers can be used, including antibodies or otherbinding partners, labels, stains, pattern analysis (for cells and cellcomponents), and in general any other chemical or visual identificationtechniques.

Markers that are presently being studied by researchers presentlyinclude, carcinoma embryonic antigen (CEA), prostate specific antigen(PSA) Erb B2 antigen, gross cystic disease fluid protein-15 (GCDFP-15),and lactose dehydrogenase (LDH). For CEA see Imayama et al., Cancer1996, 78(6):1229-34; Inaji et al., Cancer 1987, 60(12):3008-13; Mori IntConger Seer 1989, 807:211-8; Inaji, et al., An To Kagaku Ryoho 1991,18(2):313-7; Yayoi, et al. Gan To Kagaku Ryoho 1994, 21 Suppl 2:133-9;Mori, et al. Jpn J Clin Oncol 1989, 19(4):373-9; Foretova, et al. ProcAnnu Meet Am Soc Clin Oncol 1995, 14:A101; and Nishiguchi, et al. RinshoByori 1992, 40(1):67-72. For PSA see Foretova, Garber Lancet 1996,347(9015):1631; Sauter et al., Cancer Epidemiology, Biomarkers &Prevention. 5(12):967-70, 1996; Sauter and Daly (1996) Proc Annu Meet AmAssoc Cancer Res 37:A1458; and Foretova and Garber (1996) Proc Annu MeetAm Assoc Cancer Res 37:A1446. For Erb B2 see Motomura (1995) BreastCancer Res and Treat 33:89-92; and Inaji et al. (1993) Tumour Biol 14:271-8. For GCDFP-15 see Petrakis et al. (1994) Proc Annu Meet Am AssocCancer Res 35:A1698. For LDH see Mannello et al. (1995) Cancer 76:152-4;and Kawamoto (1994) Cancer 73:1836-41.

Chromosomal abnormalities in ductal epithelial cells can also provideinformation and act as a marker to identify cancer or precancer asdescribed in Mark et al. (1999) Cancer Genet Cytogenet 108:26-31;Lundlin and Mertens (1998) Breast Cancer Res Treat 51:1-15; Newsham(1998) Am J Pathol 153:5-9; Larson et al. (1998) Am J Pathol 152:1591-8.Adelaide et al. (1998) Genes Chromosomes Cancer 22:186-99; Fejzo et al.(1998) Gene Chromosome Cancer 22:105-113; Dietrich et al. (1998) HumPathol 12: 1379-82; Cavalli et al. (1997) Hereditas 126:261-8; Adeyinkaet al. (1997) Cancer Genet Cytogenet 97:119-21; Afify and Mark (1997)Cancer Genet Cytogenet 97:101-5; Brenner and Aldaz (1997) Prog Clin BiolRes 396: 63-82; Mark et al. (1997) Ann Clin Lab Sci 27:47-56; and Fabianet al. 1993 J Cellular Biochemistry 17G: 153-16.

In addition, exemplary markers are described in Masood, (Prediction ofrecurrence for advanced breast cancer. Traditional and contemporarypathologic and molecular markers) Surgical Oncology Clinics of NorthAmerica. 4(4):601-32, 1995; Lopez-Guerrero et al. (1999) J Hematother8(1):53-61; Maijumdar and Diamandis (1999) Br J Cancer79(9-10):1594-602; Balleine et al. (1999) Br J Cancer 79 (9-10):1564-71;Houston et al. (1999) Br J Cancer 79(7-8):1220-6; Nikolic-Vukosavljevicet al. (1998) Tumori 84(6):691-4; Maguire et al. (1998) Int J BiolMarkers 13(3):139-44; Stearns et al. (1998) Breast Cancer Res Treat52(1-3):239-59; Eiriksdottir et al. (1998) Eur J Cancer 34(13):2076-81,and U.S. Pat. No. 5,169,774. Many known breast cancer markers arediscussed and described in readily available medical textbooks on breastcancer.

The morphology of the cells or cellular contents that are trapped in theduct by the gel may also be examined. The cellular contents can include,e.g. protein, nucleic acid, or other molecular markers in the cells.Cell morphology can serve to establish whether the ductal epithelialcells are normal (i.e. not precancerous or cancerous or having anothernoncancerous abnormality), precancerous (i.e. comprising hyperplasia,atypical ductal hyperplasia (ADH) or low grade ductal carcinoma in situ(LG-DCIS)) or cancerous (i.e. comprising high grade ductal carcinoma insitu (HG-DCIS), or invasive carcinoma). Analysis of cell contents mayserve to establish similar staging as established by morphology,capturing generally a progression of a precancerous or cancerouscondition in the cells.

Ductal epithelial cells can be tested for the presence of estrogenreceptor for example by any standard technique available for detectingthe presence of proteins generally in cells. Some assays provide methodsto quantify the results of the tests. Normal cells of the ductalepithelium can be expected to have a high base line of estrogenreceptor, i.e. all normal ductal epithelial cells can be expected tostain or register positive for estrogen receptor. Cells that becomeprogressively cancerous, moving from normal to precancerous to cancerouscan be expected at some point in that continuum to have more and moreductal epithelial cells that do not have estrogen receptor. Assays fortesting for the presence of ER can include standard tests forintracellular receptors. Assays to test for ER presence can also beconducted, e.g. as described in Jacobs et al., (1996) Eur J Cancer32A:2348-53, Pertschuk et al., (1996) Gynecol Oncol 63:28-33, Molino etal., (1995) Breast Cancer Res Treat 34:221-8, Esteban et al., (1994) AmJ Clin Pathol 102:158-62, Pertschuk et al., (1994) J Cell Biochem Suppl19:134-7, Poller et al., (1993) Br. J Cancer 68:156-61, Chapman et al.,(1993) J Steroid Biochem Mol Biol 45:367-73, Davies et al., (1991) Ann RCoil Surg Engl 73:361-3, Sklarew et al., (1990) Cytometry 359-78, Mobuset al., (1998) Int J Cancer (1998) 77(3): 415-23, Mohamood et al.,(1997) J Submicrosc Cytol Pathol 29(1):1-17, and Jensen, EV, (1996) AnnNY Acad Sci 784:1-17. Estrogen receptor immunocytochemistry ER-ICA(available from Abbott laboratories, located in Abbott Park, Ill.) canbe used to identify and quantify the ER from a sample of ductalepithelial cells in order to establish an ER positive condition ofductal epithelial cells in the milk duct. The ER-ICA test has been usedin FNA procedures to identify estrogen receptors as describe in Azavedoet al., (1986) Anticancer Research 6:263-266; Fabian et al. (1997) JCell Biochem Suppl 28-29: 101-110; Flowers et al. (1986) Ann. Surg.203:250-254; McClelland et al., (1987) Cancer Research 47: 6118-6122;Sauer et al. (1998) Anal Quant Cytol Histol 20(2): 122-126; Tabbara etal. (1998)

Cancer 84(6): 355-360. Other analysis using estrogen receptors includethose described in Masood S., (Prognostic and diagnostic implications ofestrogen and progesterone receptor assays in cytology) DiagnosticCytopathology 10(3):263-7, 1994; and Masood et al., (Potential value ofestrogen receptor immunocytochemical assay in formalin-fixed breasttumors) Modern Pathology. 3(6):724-8, 1990.

For example the gel-filled breast duct can also be used to detect thepresence of TGF-β in the ductal fluid trapped by the gel. The ductalfluid and/or ductal epithelial cells contained in the gel can beanalyzed for the presence of transforming growth factor-beta (TGF-β).The presence or amount of TGF-β in a fluid or sample is measured againsta control, e.g. the presence or amount of TGF-β in a normal sample.Standard ELISA tests (e.g. ELISA tests available from companiesproviding assays and reagents for molecular biology, e.g. PromegaCorporation, located in Madison, Wis.) for TGF-B can be used. Anotherexemplary means of testing for TGF-β can be polymerase chain reaction(PCR) protocols to test levels of TGF-β mRNA encoding the protein, orother appropriate standard tests for testing protein or transcriptlevels can also be used. Standard detection assays for proteins or RNAtranscripts of genes such as TGF-β are provided by standard protocolbooks, e.g. in Sambrook, 1989, Molecular Cloning, A Laboratory Manual,2d Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.,and Ausubel et al., Current Protocols in Molecular Biology, 1987-1997Current Protocols, 1994-1997 John Wiley and Sons, Inc. In addition,TGF-β can be tested as described in Li et al., (1998) J Immunol Methods218:85-93 (either bound or unbound from its receptor), Li et al., (1998)Int J Cancer 79:455-459, Plath et al. (1997) J Endocrinol 155:501-11,Amoils et al. (1996) Br J Cancer 73:1255-9, Walker and Gallacher (1995)J Pathol 177:123-7, Danielpour and Roberts (1995) J Immunol Methods180:265-71, and Gall et al. (1993) J Clin Pathol 46:378-9, Walker andDearing (1992) Eur J Cancer 28: 641-4, and Relf et al. (1997) Cancer Res57:963-9.

The following are more exemplary potential markers for such diagnosisand analysis or treatment of the gel-filled breast duct. The diagnosis,analysis or treatment can be implemented by placing these diagnostic ortherapeutic additives in the composition for delivery to the targetbreast duct. Exemplary markers or additives can include the following orlike molecules with like effects:

-   -   cathepsins (including cathepsin D)    -   maspin, fas, fas ligand, tissue inhibitor of matrix        metalloproteinas-1 (TIMP-1)    -   chemokines (both C—C and C—X—C type chemokines)    -   collagenases, metalloproteinases, TIMP's, cathepsins, disrupted        basement membrane epitopes, stromolysin-3    -   cytokeratins (e.g. keratin 14, B1, KA1, KA4 and 312C8-1)    -   estrogen and progesterone receptors (or any androgen or other        steroid receptor)    -   growth factor receptors for members of the fibroblast growth        family (FGF) including FGF1-18, vascular endothelial growth        factor (VEGF), insulin-like growth factor-1 (IGF-I), IGF-II,        platelet-derived growth factor (PDGF), keratinocyte growth        factor (KGF), and epithelial growth factor (EGF), placental        growth factor (PLGF), hepatocyte growth factor (HGF), tumor        necrosis factor (TNF), transforming growth factor (TGF) both        alpha and beta forms, and angiopoietin, for example    -   growth factors and cytokines including FGF1-18, VEGF, IGF-I,        IGF-II, PDGF, KGF, EGF, PLGF, HGF, TNF, TGF alpha and beta,        angiopoietin, for example    -   heat shock proteins (HSP) (e.g. HSP27) 27 (HSP27)    -   ErB type 1 tyrosine kinase receptors (e.g. Her2 (an EGF        receptor) or any ligand or receptor of the ErbB family of        ligands and receptors)    -   integrins, selectins, cadherins, for example (i.e. alpha and        beta 3 integrin)    -   keratin-14    -   known cancer antigens including, for example Ki-67, Ki-S1, p53,        nm23, bcl-2, p21 ras, cyclins, and pS2    -   Thrombin receptor activating peptide    -   urokinase, urokinase-type plasminogen activator (UPA), plasmin        antiplasmin, UPA receptor (UPAR), fibrinogen, plasmin activator        inhibitor-1 and 2 (PAI-1 and 2)    -   telomerase    -   antibodies to tumor associated antigen-72 (TAG-72) (e.g. B72.3,        B6.2, and TKH2)    -   carcinoembryonic antigen (CEA)    -   prostate specific antigen (PSA)    -   S1 protein    -   alkaline phosphatase    -   myosin    -   sialyl Tn (STn) glycopeptide (e.g. TAG-72)    -   Tn glycopeptide    -   aneuploidy and/or other chromosomal mutations

The biocompatable gel composition can also be used to make a ductal mapof an entire breast where all the ducts are filled in order to aid asurgeon for any procedure involving multiple ducts or a large portion ofthe breast. In the case where some ducts are filled without intention toexcise the duct, the particular biocompatable gel composition useful formapping the breast ducts (or nearly all the breast ducts) in a givenbreast are required to be not only biocompatable but also biodegradable,so that after a reasonable period of time (e.g. a few days, a week, afew weeks, or a month or two) the material in the preserved breast ductsbiodegrades and the ductal function can return to normal and the lumensof the ducts are essentially cleared of the gel.

In order to use the biocompatable, biodegradable gel composition of theinvention, the ducts of the breast can be filled with the liquidcomposition as described above, with the additional steps that all theducts (or nearly all the ducts) are accessed and filled with the gelcomposition. The ducts can be filled at about the same time, or as closeto the same time as possible. Thus the ducts can be filled sequentiallyor essentially simultaneously before the surgical procedure. The gelcomposition in the breast ducts can undergo a gel transition asdescribed above. The hardened or semi-hardened or viscous gel can beidentified by visible color, color detectable with a special light (e.g.UV or fluorescent light) or other detection means in order to guide thesurgeon according to the goals of the surgery.

Additives in addition to detection or identification additives may beplaced in the gel for mapping the ducts in the breast, including, e.g.therapeutic additives. The therapeutic additives may be, e.g. additivesto aid in healing the breast after the breast surgery. The additives maybe either retained in the biodegradable gel, or be permitted by the gelmatrix and gel transition chemistry to seep from the duct through theductal wall and into surrounding tissue. In the surrounding tissue,therapeutic additives, e.g. antibiotics, or wound healing additives, mayaid the breast tissue to heal after the tissue removable procedure.

The invention provides a process or method for forming an in vivo gelmap of a breast duct. The in vivo gel map provides apractitioner/surgeon with a map of a target duct to be excised providingthe opportunity to remove the entire duct cleanly, and to leave behindas much benign breast tissue as possible. A gel composition in a ductalso can provide an aide to removing a lump in the breast (lumpectomy),removing part of a duct, removing the entire duct (partial or completeductectomy), or performing a partial or complete mastectomy. In the caseof a mastectomy, the gel composition can aid a surgeon to retrieve allor most all parts of the duct or ducts targeted for excision of thebreast and thus decrease the likelihood of a reoccurrence of the cancer.Where the additive is a dye or colorant that can be seen through theskin of the breast, a portion of the target duct may be seen fromoutside the breast after delivery of the composition but before anyincision is made in the tissue. The ability to see the location of theduct from outside the breast can aid a surgeon in choosing the site foran initial incision and for devising a surgical plan for removal of theduct in order to preserve as much healthy breast tissue as possible.

The process begins by administering to a target breast duct abiocompatable composition comprising a polymer in a solvent capable of agel transition inside the target duct. Where multiple ducts are to beexcised, or a partial or complete mastectomy is to be performed,multiple ducts are filled with the gel composition. The biocompatablecomposition can be any such composition, including, e.g. compositionsdescribed and cited to herein. The biocompatable composition willcomprise a biocompatable polymer and solvent so that the gel compositionis a liquid before and during delivery to the target breast duct. Later,once inside the target duct the composition can undergo a gel transitionand become a non-liquid gel.

The composition is preferably a liquid at room temperature (i.e. atemperature in a range from about 22° C. to about 27° C.) and undergoesa gel transition once inside the target duct within about 30 minutes ofdelivery of the composition. Alternatively, the gel transition begins asthe composition is delivered and the gel completes the transition sometime during or after delivery of the composition to the duct. The gelcomposition can therefore undergo the gel transition a few minutes afterdelivery of the first portion of the gel to the target duct. The geltransition can begin e.g. at 0 to 1, or 1 or 2 minutes after delivery isbegun of the first portion of the composition to the breast duct, orfrom about 0 to about 2 minutes, or about 2 to about 5 minutes fromdelivery of the first portion of the composition to the breast duct, orfrom about 5 to 10 minutes from delivery of the first portion of thecomposition to the breast duct, or from about 10 to 20 minutes fromdelivery of the first portion of the composition to the breast duct, orfrom about 20 to 30 minutes from delivery of the first portion of thecomposition to the breast duct. Depending on the final hardness orviscosity of the gel and other parameters or variables such as the lumensize of the delivery tool, the condition change that causes the geltransition, the starting time of gelation, the amount of time it takesfor gelation to be complete, the optimal start time and rate can varyand still provide suitable conditions for the method steps.

The composition is administered using a breast duct access tool having alumen small enough to access a breast milk duct. A catheter may be usedas the access tool. The lumen of the access tool may be as large as 0.10inches in diameter, or in a range from about 0.09 to 0.05 inches indiameter, or in a range from about 0.04 to about 0.025, or in a rangefrom about 0.024 to about 0.010 inches in diameter. The access tool canbe any tool capable of accessing a breast milk duct and delivering a gelsolution as a liquid. Thus, e.g. the access tool can be a catheter, acannula, a needle having a lumen, or other lumen containing tool capableof fluid delivery to a breast milk duct.

Access of a breast duct can be facilitated as described in e.g. Love &Barsky, (1996) Lancet 348: 997-999, Makita et al. (1991) Breast CancerRes Treat 18: 179-188, or Okazaki et al. (1991) Jpn J. Clin. Oncol.21:188-193. Other descriptions of ductal access may be applied to thetask of delivering a gel composition, including, e.g. Sartorius et al.,“Contrast ductography for recognition and localization of benign andmalignant breast lesions: an improved technique” pp. 281-300. In: LoganW W, ed. BREAST CARCINOMA. New York, Wiley, 1977. WP 870 B8278 1977;Barsky and Love (1996) “Pathological analysis of breast duct endoscopedmastectomies” Laboratory Investigation, Modern Pathology, Abstract 67;Lewis (1997) Biophotonics International, pages 27-28, May/June 1997;Diner et al. (1981) American J Radiology 137: 853; Tabar et al. (1983)Radiology 149: 31; and Threatt et al. (1987) DUCTOGRAPHY p. 119 Bassetand Gold eds, Grune & Stratton, Orlando. A tool such as described incopending and co-owned application U.S. Ser. No. 09/473,510 filed Dec.27, 1999 may also be used for delivery of the composition to the targetbreast duct. For simultaneous delivery of the composition to multipleducts, a tool as described in copending and co-owned application U.S.Ser. No. 09/506,477 filed Feb. 29, 2000 can be used.

The principles of access of the duct include that the ductal lumen isaccessed through the ductal orifice. A medical tool can be placed in theduct so that its distal tip is just below the ductal orifice.Alternatively the tool can be placed just below the sphincter of thelactiferous sinus, or alternatively further into the duct. The tool maybe positioned so that it contacts with fluid in the duct. The tool mayalso be positioned so that it contacts the lesion in the duct. Thus, thetool can be placed just below the nipple surface, or more distal, e.g.to the lactiferous sinus and beyond. The gel delivery can be facilitatedwith a medical tool, e.g. a catheter, cannula, shunt, stent or othersuitable delivery tool.

The composition used in the process of making the in vivo gel map canhave additives that aid in detecting the duct so that the practitionercan find the duct for surgical excision. The composition can also havediagnostic or therapeutic additives as described above.

The invention provides for a kit for mapping a breast milk duct with anin vivo gel (in preparation for surgical excision of the duct, a part ofthe duct, a lump, or the breast or part of the breast) comprising abiocompatable composition that is liquid at room temperature. Thebiocompatable composition undergoes a gel transition in a breast ductwithin 30 minutes of delivery to the target duct. The kit can furthercomprise a ductal access and delivery tool, e.g. a catheter, stent orshunt, for delivery of the composition to the target breast duct. Thetool will have an access lumen small enough to access a breast milkduct, which sizes are described above. The kit also comprises acontainer for the kit contents and instructions for use of the kit. Theinstructions for the use of the kit can include instructions on how tostore and prepare the biocompatable composition for delivery, how todeliver the composition to the breast duct using a catheter, how toidentify the gel-filled breast duct during a procedure includingsurgical excision of the duct, and how to review the surrounding tissuefor whether the duct is excised in its entirety and the margins areclean. Further, where therapeutic or diagnostic additives are present inthe composition, how they may be used to treat the wound after surgeryor diagnose any lesions in the breast duct can be described in theinstructions. The instructions pertaining specifically to the surgeryprocedures can read very much like the disclosure on page 69 of GoodsonW H & King E B, Chapter 4: Discharges and Secretions of the Nipple, TheBreast: Comprehensive Management of Benign and Malignant Diseases (1998)2nd Ed. vol 2, Bland & Kirby eds. W.B. Saunders Co, Philadelphia, Pa.pp. 51-74, or other surgical directive pertaining to a procedure toremove a breast milk duct.

The invention includes a method for identifying one or more breast ductsin a breast for providing a surgeon guidance in a procedure to removesome or all breast tissue from the patient by administering to one ormore breast ducts in the target breast a biocompatable compositioncapable of a gel transition inside a breast duct. During the procedure,the presence of the gel inside the duct provides identification of theduct during surgery. Also, if an additive is present in the compositionthat is visible from outside the breast, the gel and composition isuseful to identify an optimal starting point and pattern for an incisioninto the breast in order to conserve as much healthy breast tissue aspossible. Thus, a method is provided for guiding surgical excision ofbreast tissue for example where the procedure is a lumpectomy, a partialductectomy, a total ductectomy, a partial mastectomy, or a totalmastectomy.

As described above for forming an in vivo gel map of a target breastduct for surgical excision of the duct, the invention also provides amethod of mapping multiple breast ducts (e.g. more than one breast duct,and preferably all or nearly all of the breast ducts in a breast) foridentifying more than one breast duct for excision, partial excision,lumpectomy, or for mastectomy (either partial or complete). Theinvention provides a process for forming an in vivo gel map of thebreast ducts in a breast for these and other purposes. The in vivo gelmap provides a practitioner/plastic surgeon with a map of the breastducts so that the ducts are identified and can either be preserved orremoved, depending on the surgeon's purpose in identifying the ducts.The process can be conducted much as the process for mapping a targetbreast duct scheduled for surgical excision by administering to a thebreast ducts (e.g. those that can be identified) a biocompatablecomposition comprising a polymer in a solvent capable of a geltransition inside the ducts. Those ducts that the surgeon intends topreserve are best filled with a gel composition that is alsobiodegradable.

The biocompatable and biodegradable composition can be any suchcomposition, including, e.g. compositions described and cited to herein.The biocompatable and biodegradable composition will comprise abiocompatable and biodegradable polymer and solvent so that the gelcomposition is a liquid before and during delivery to the breast ducts.Later, once inside the ducts the composition can undergo a geltransition and become a non-liquid gel, e.g. a viscous or hardened gel.

EXAMPLES

1. Testing Visible Dyes and Other Additives for Affects on Gelatin

The purpose of the experiment was to determine the feasibility ofinjecting radiopaque material together with hydrogel having variousvisible dyes into the milk ducts. To determine which dyes can be usedalone and in combination with each other with formulations containinghydrogel and radiopaque material for injection into the milk ducts. Thevisible dyes tested included methylene blue, isosulfan blue,fluorescein, and green food dye. Visualization of the fluorescein waspossible with a UV light, and also somewhat by the naked eye.

One duct from each nipple from 2 rabbit pelts (available fromPel-Freez™) and one mature live rabbit (# 4923) (available from KraelikFarms (located in Santa Cruz, Calif.) were catheterized with a 0.011inches tip Pebax™ catheter and coinjected with 0.1-1 ml of cold (4° C.)hydrogel (Pluronic F-127) in a range of amount from 18% to 20%. The gelcontained the radiopaque substance Hexabrix (12-12.7%) with or withoutthe dyes mentioned. Some nipples from live rabbits were cooled prior toinjection with bags of ice for 5 minutes or so. After all target nippleswere injected, the skin was carefully dissected away from the underlyingtissue so that the ducts could be observed. The injected ducts wereobserved for the extent that the hydrogel could be seen, and the extentto which the duct had been filled. After observation, the ducts weresliced longitudinally and in cross-section with a scalpel to determinethe solidity and texture of the hydrogel mixture.

The results of the hydrogel injections indicated that the ducts andapparently at least some of the lobules in one quadrant of each of theinjected nipples were filled with colored hydrogel. In some cases thehydrogel probably did not extend all the way to the end of the lobule.The hydrogel formulations that were used remained intact in the ductseven after they were longitudinally cut. Injection of green food colorgave the best contrast; isosulfan blue and methylene blue were probablyalso acceptable. Fluorescein diffused out of the ducts after injection,and may be usable if formulated in a manner that encourages ductalretention of the fluorescein molecules. In addition, in the liveanimals, the hydrogel flowed further into the ducts in animals where thebreast tissue was precooled with ice. See Table I below for details ofthis experiment for each infusion. TABLE I Results of Rabbit Pelt andLive Rabbit Gel Composition Injections Identifier % Gel ml AdditivesTool Temp Results 1 rabbit pelt 1; 18% F-127 0.4 ml Hexabrix 12.2%;Pebax 4° C. gel never solidified nipple 1 (form A) no dye 0.011-0.012″ 2rabbit pelt 1; 20% F-127 0.5 ml Hexabrix 12.2%; Pebax RT became solidnipple 2 (form B-1) no dye 0.011-0.012″ quickly; resistance to injectionat the end of the procedure 3 rabbit pelt 1; 20% F-127 0.5 ml Hexabrix15%; Pebax RT green color noted; nipple 3 (form B-3) 1% methylene0.011-0.012″ good diffusion blue; 2% through the duct fluorescein 4rabbit pelt 1; 20% F-127 0.7 ml Hexabrix 27%; Pebax RT moderatedifficulty nipple 4 (form B-2) 1% methylene 0.011-0.012″ in injection;good blue; 2% color/visibility fluorescein 5 rabbit pelt 1; 20% F-1270.9 ml Hexabrix 15%; Pebax RT brilliant network of nipple 5 (form B-3)0.06% methylene 0.011-0.012″ green blue; 0.12% fluorescein 6 rabbit pelt1; 20% F-127 0.5 ml no Hexabrix; 1 Pebax RT see green duct and nipple 6(form B) drop green food 0.011-0.012″ green ductal color lobules andfeathery portions of the lobules; color might be more intense withlarger dose of dye 7 live rabbit 4; 20% F-127 0.3 ml Hexabrix 15%; PebaxRT easy injection - no nipple 1 (form B-3) 1% methylene 0.011-0.012″resistance; at first blue; 2% some flowed out of fluorescein the nipple;after animal sacrificed similar to nipple 2 below. 8 live rabbit 4; 20%F-127 0.3 ml Hexabrix 15%; Pebax on ice easy injection - no nipple 2(form B-3) 0.06% methylene 0.011-0.012″ resistance; duct full blue;0.12% nearly to ends; fluorescein after animal sacrificed fluoresceinstained tissue outside the duct - dye stained gel inside the duct 9 liverabbit 4; 20% F-127 0.3 ml + 0.7 ml Hexabrix 27%; Pebax on ice catheterplaced nipple 3 (form B-2) green food color 0.011-0.012″ inside 5 mm;after 3 ml, put in another 7 ml; after animal sacrificed: duct green -good visual of ductal structure 10 live rabbit 4; 18% F-127 0.5 ml nocolor; Pebax on ice gel solidified, nipple 4 (form A) Hexabrix 12.5%0.011-0.012″ caught in catheter after catheter popped out of duct 11live rabbit 4; 20% F-127 0.5 ml isosulfan blue Pebax on ice catheterpopped out nipple 5 (form B) (0.65 g) 0.011-0.012″ after 0.5 ml; gelfluorescein (0.85 flowed nicely g) along duct - color visible from theoutside of the animal; after animal sacrificed infection noted in theduct2. Rabbit Duct Detection by Fluoroscopic Hydrogel

The purpose of the experiment was to determine if ducts injected withhydrogel plus radiopaque additive (Hexabrix) alone and also with otherdye can be visualized by fluoroscopy. The experiments also aimed todetermine the differences in fluoroscopic intensity of injections ofdifferent concentrations of the radiopaque compound Hexabrix informulations of hydrogel.

One rabbit (rabbit 1) from BABCO (located in Berkeley, Calif.) wasshaved and placed supine. Nipples one through nine were identified andmarked. Using a dissecting microscope to see the ducts, forceps wereused to remove keratin plugs at the ductal orifices.

The pre-prepared hydrogel solutions (A, B2, B3) were stored atrefrigerated temperatures, and placed on ice until use. Thethermosensitive isotonic hydrogel solutions were prepared from Pluronic™products available from BASF through Sigma Chemicals (located at St.Louis, Mo.), Pluronic F-127 catalogue number P-2443. Basic formulation Acontained 20 g of pluronic F-127 polymer and 90 g of phosphate bufferedsaline (PBS), resulting in an 18% solution. Basic formulation Bcontained 20 g of pluronic F-127 polymer and 80 g of purified water fora 20% solution. Dyes and contrast agents were added to these basicformulations as follows:

A received 1.5 g Hexabrix contrast agent for a 12 g and 12.5% loadingpercentage;

B-1 received 1.5 g Hexabrix contrast agent for a 12.3 g and 12.2%loading percentage;

-   -   B-2 received 2.74 g Hexabrix contrast agent for a 10.05 g and        27% loading percentage;    -   B-3 received 1.47 g Hexabrix contrast agent for a 9 g and 15%        loading percentage.

The solutions flowed at from 2° C. to 8° C. The solutions formed a stiffhydrogel at 37° C.

Test 1. A 1 cc syringe having a Luer-Lok™ tip was filled with hydrogelsolution B-2. A catheter (diameter 0.011 inches) was inserted into aduct. A LuerLok™ syringe was attached to the catheter, and the hydrogelfrom the syringe was injected into the duct. The gel began geltransition between 30 seconds and 1 minutes after entry into the duct.Pictures were taken of the duct in the breast before surgical cutting.The tissue was separated from the gel-filled duct; the extent of gelspread through the duct was noted; and a cross-section of the duct wasmade to assess solidity of the gel. The gel-filled duct was excised, andpreserved for further analysis. The procedure was repeated for otherducts of each rabbit.

The conclusions drawn from this experiment were that a 27% Hexabrixcontrast agent combined with the Pluronic hydrogel could be readilyinjected and detected by fluoroscopy. The formulation used was able totravel nearly to the ends of the ducts as indicated by the addition ofthe dye. The contrast agent was visible through a significant part ofthe ducts but was not always visible in the small distal ends of theducts even though the hydrogel traveled that far. As indicated bycontrast and dye, a thin line of hydrogel is visible going down thenipple, the diameter of which expands considerably towards the end ofthe injection. Just below the nipple is a collection of hydrogel,presumably in the lactiferous sinus. More distally, the hydrogel isvisible fanning out into a thinning ductal network. Table 2 belowsummarizes the experiment. Conclusions that were drawn from theexperiments in Table 2: the slower the injection the more completely theduct was filled; hydrogel was observed to the ends of the ducts; 27%contrast goes to the near ends of the ducts. but was faint. TABLE 2Radiopaque Contrast Agent and Visible Dye Additives # identifiercontrast and other dye comments 1 R1- nipple 6- form B-2 (27% hexabrix +injection was easy at first (0.5 cc) and then duct1 20% hydrogel) becamedifficult 2 R1- nipple 7- form B-2 (27% hexabrix + injection hadconstant resistance duct 1 20% hydrogel) 3 R1- nipple 8 - from B-3 (15%hexabrix + resistance in delivery; solid hydrogel exited duct 1 20%hydrogel) the duct 4 R1- nipple 5- 10% hydrogel + isosulfan very faintspot observed around nipple duct 1 blue and fluoroscein 5 R1 - nippleform B2 (27% hexabrix + moderate to heavy resistance, but less 3- duct 120% hydrogel) resistance at the end - the sinus may have been perforated6 R1 - nipple from B3 (15% hexabrix + resistance moderate to light; spotvisible 2- duct 1 20% hydrogel) plus slightly on nipple surface;catheter popped methylene blue & flourescein out 7 R1- nipple 2- form B3(15% hexabrix + a tree like ductal structure visible duct 2 20%hydrogel) plus methylene blue & flourescein 8 R1 - nipple form B-2 (27%hexabrix + injected slowly 6- duct 2 20% hydrogel) 9 R1- nipple 1- formB-2 (27% hexabrix + injected slowly (during 45 seconds); the duct 1 20%hydrogel) with food ducts are visible, but no food color lines coloringthem3. Colored Hydrogel Introduced into a Duct of a Mastected Breast

One duct from a mastected human breast was cannulated with a petitecatheter and the duct infused with formulation B (20% Pluronic F127)with methylene blue colorant added. The liquid formulation infusedeasily; in 15 seconds 0.5 cc was infused. The gel solidified promptly.The breast was squeezed and a little bit of the gel escaped at thenipple surface.

4. Hydrogel Formulation Evaluation

The purpose of this experiment was to develop optimal hydrogelformulations and evaluate them in both bench top and animal models. Todetermine the optimal hydrogel formulation, formulations will be testedmainly for solidification times and solidification temperatures. Inaddition to characterizing the hydrogels physically, other parameterssuch as hydrogel travel distance, color contrast, texture, etc. will beexamined in an animal model. Some hydrogels will be tested prior to andfollowing autoclaving to determine the effect of this sterilizationtechnique on the hydrogel formulations. The visible dyes tested will beFD&C approved dyes, specifically Blue #1, Yellow #5, and Verdant GreenMx-135 (Pylam Products Company, Inc.; Tempe, Ariz.).

Bench top evaluation of hydrogel formulations involved testing in awater bath system, and measuring parameters such as solidification timesand solidification. All hydrogel formulations were made from PluronicF-127 in the concentration range from 14-15%. Preliminary data onhydrogel formulations developed in the 15-18% range indicate thatsolidification temperatures were lower than desired; therefore theextensive evaluation of these formulations did not occur at this time.All hydrogel formulations consisted of one of the three visible dyesthat were being tested: yellow, blue, or green. Solidificationtemperature was determined by placing the hydrogels in a water bath atset temperatures in the range of 25-37° C., in increments of 3° C. Thisrange of temperature was chosen to mimic the clinical setting andphysiological environment that the hydrogels would experience. After thewater bath achieved the desired temperature, the hydrogel was placed inthe bath and allowed to incubate for 15 minutes prior to evaluation.Evaluation consisted of visual inspection to determine if theformulation was liquid, viscous, solid, or any other combination ofthese descriptive factors (i.e. liquid/viscous, viscous/solid, orliquid/solid). Solidification time testing consisted of placing theindividual hydrogel formulations in a water bath that is at 37° C. anddetermining, every minute up to 20-30 minutes, the state of the hydrogelcomposition. Evaluation, like the solidification temperature, consistedof visual inspection for determination if the formulation was liquid,viscous, and/or solid. It should be noted that testing of most hydrogelcompositions occurred pre and post autoclaving to determine the effectthis sterilization technique had on all the above mentioned parameters.

Animal testing consisted of evaluation of the above parameters in a liverabbit model. A rabbit was anesthetized and placed in the supineposition. The abdomen was shaved to allow exposure of the nipples. Oneor two ducts from each nipple of a rabbit were catheterized with a Pebaxcatheter (tip diameter 0.011″-0.012″). Once the catheter tip was inplace, approximately 0.1-1.5 ml of hydrogel was injected into the ductalsystem. Some nipples were cooled prior to injection of hydrogel withbags of ice for approximately 2 minutes. All hydrogel injected wascooled to 4° C. and in some cases the catheter was cooled prior to andduring the delivery process of the hydrogel. In addition, after thehydrogel was administered into the ductal system, some nipples wereheated with a lamp in order to facilitate quicker solidification. Afterall nipples were targeted, the skin was carefully dissected away forvisualization of the underlying tissue that contains the ductal system.The injected ducts then could be viewed for evaluation of parameterssuch as hydrogel travel distance, solidification, etc. Lastly, the ductswere observed for solidification and texture by slicing the ducts bothlongitudinally and in cross-section. Hydrogel formulations wereevaluated after.

The results for the bench top testing as presented in Table 3 displaythe data solidification times, and solidification temperature andcharacteristics of the hydrogels. Table 3 reports results for both preand post-autoclaved hydrogel. Table 4 reports the results of hydrogelformulation evaluated in a live rabbit model. All formulations tested inthe rabbit model were post-autoclaved hydrogels.

From bench top testing (Table 3), in general, the higher the percentageof pluronic, the quicker the solidification time and lower thesolidification temperature for pre-autoclaved formulations. Majority ofthe formulations solidified at temperatures that were ≧31° C. Sinceinternal temperature of the body is approximately 37° C., theseformulations meet the physiological characteristics of a hydrogelproduct. In addition, all formulations were liquid at room temperaturewhich is desired for any formulation for ease of introduction via thecatheter into the ductal system (data not indicated in Table 1).Comparing pre-autoclaved formulations to post-autoclaved formulationsindicates a shift in solidification temperatures. Most hydrogels reducedsolidification temperatures and in doing so, this resulted in anincrease in the time to solidify. There does not appear to becorrelation between specific color additive and alterations in hydrogelcharacteristics. Therefore, any of the color dyes that provide the bestcontrast with surrounding tissue can be utilized in this device.

Table 4 reports results from an animal study. In this table are a seriesof nipples that were tested on an isolated rabbit with several differenthydrogels that were composed of different percentage of hydrogel, andvarious color dyes. Data reported is introduction time, gelation time,and travel distance. Quantity of hydrogel delivered to each ductalsystem varied. This was dependent on how much of hydrogel could flowinto the duct prior to the gelation process occurring. When hydrogeltraveled to the distal portion of the ductal system, approximately 1-2ml of composition could be introduced. If wheals formed at the base ofthe nipple, thereby blocking the rest of the ductal systemapproximately, only 0.5 ml of hydrogel could be introduced. Hydrogeldelivery time was ˜≧3 minutes, this includes times where it wasdifficult to introduce hydrogel as well. To reduce the amount ofdelivery time, ice was applied to either the nipple or the syringe orboth. By icing the nipple, this kept the hydrogel in a liquid state andmade for easier introduction of the hydrogel. Following introduction ofhydrogel it took approximately 2-7 minutes for gelation to occur. Longersolidification times could be due to the surrounding tissue being cooledand needed to rise to 37° C. or internal body temperature. In the casewhere a heat lamp was used, the gelation process was quicker andoccurred within one minute. In this experiment, blue dye appeared toprovide better contrast with the surrounding tissue than green dye.However, it should be noted that the green dye was faint and could notbe seen well. Creating a darker green dye will alleviate the faintnessissue and provide another option for hydrogel coloring. TABLE 3Pre/Post-Autoclave Hydrogel Formulation Evaluation Bench Top TestingSolidification Solidification Item % Gel Date Solvent Dye color TempPre/Post (° C.) Time Pre/Post (min) 1 14.5 (B) 10 May 2000 Water Blue37/34 12/10 2 14.5 (G) 10 May 2000 Water Green 37/34 12/10 3 14.5 (Y) 10May 2000 Water Yellow 37/34 12/10 4 14.6 (B) 10 May 2000 Water BlueNA/NA NA/NA 5 14.6 (G) 10 May 2000 Water Green NA/NA NA/NA 6 14.6 (Y) 10May 2000 Water Yellow NA/NA NA/NA 7 14.7 (B) 10 May 2000 Water Blue31/31 3/4 8 14.7 (G) 10 May 2000 Water Green  34/>37 5/5 9 14.7 (Y) 10May 2000 Water Yellow 34/28 5/2 10 14.8 (B) 10 May 2000 Water Blue 31/284/4 11 14.8 (G) 10 May 2000 Water Green 31/34  7/17 12 14.8 (Y) 10 May2000 Water Yellow 31/31  7/19 12 14.0 (B) 06 Apr. 2000 Water Blue NA/>37  NA/>15 13 14.0 (G) 06 Apr. 2000 Water Green  NA/>37  NA/>15 1414.2 (B) 06 Apr. 2000 Water Blue  NA/>37  NA/>15 15 14.2 (G) 06 Apr.2000 Water Green  NA/>37  NA/>15 16 14.4 (B) 06 Apr. 2000 Water BlueNA/37 NA/12 17 14.4 (G) 06 Apr. 2000 Water Green  NA/>37 NA/12 18 14.6(B) 06 Apr. 2000 Water Blue NA/31 NA/4  19 14.6 (G) 06 Apr. 2000 WaterGreen NA/31 NA/4  20 14.8 (B) 06 Apr. 2000 Water Blue NA/31 NA/4  2114.8 (G) 06 Apr. 2000 Water Green NA/31 NA/4  22 15.0 (B) 06 Apr. 2000Water Blue NA/31 NA/3  23 15.0 (G) 06 Apr. 2000 Water Green NA/31 NA/4 24 14.0 (B) 06 Apr. 2000 PBS Blue  NA/>37  NA/>15 25 14.0 (G) 06 Apr.2000 PBS Green  NA/>37  NA/>15 26 14.2 (B) 06 Apr. 2000 PBS Blue  NA/>37 NA/>15 27 14.2 (G) 06 Apr. 2000 PBS Green  NA/>37  NA/>15 28 14.4 (B)06 Apr. 2000 PBS Blue  NA/>37  NA/>15 29 14.4 (G) 06 Apr. 2000 PBS Green NA/>37  NA/>15 30 14.6 (B) 06 Apr. 2000 PBS Blue NA/31  NA/>15 31 14.6(G) 06 Apr. 2000 PBS Green NA/31 NA/4  32 14.8 (B) 06 Apr. 2000 PBS BlueNA/31 NA/3  33 14.8 (G) 06 Apr. 2000 PBS Green NA/31 NA/5  34 15.0 (B)06 Apr. 2000 PBS Blue NA/25 NA/2  35 15.0 (G) 06 Apr. 2000 PBS GreenNA/25 NA/2 

TABLE 4 Pre/Post Autoclaved Hydrogel Evaluation Live Rabbit Model NippleIntroduction Volume Gelation No. Form. Time (min) (ml) Time (min) TravelDistance Comments 1 Nipple not — — — — — used. 2 14.8(B) H₂0 1.5-2  1-1.5 ˜5 End of ductal system Blue very good contrast (6 Apr. 2000)color. Difficult at first Iced nipple and syringe and flow becameeasier. 3 14.6(G) H₂0 2 .7 ˜6 Not to ends of system. No icing of nipple.(6 Apr. 2000) Wheal at base of nipple, 14.6(B) H₂0   1-2 .6 ˜7 Not toends of system. No ice. (6 Apr. 2000) Wheal at base of nipple, 4 15.0(B)H₂0 2.5-3 .5 ˜1 Wheal at base of nipple Iced nipple for easier (6 Apr.2000) flow. Used heat lamp to gel quicker 5 Nipple not — — — — used 6Nipple not — — — — used 7 14.8(G) H₂0 2 1.5-2.0 ˜2 End of ductal systemDifficult at first, needed (6 Apr. 2000) to ice nipple and syringe.Green color too light. Darker would be better. 8 14.8(B) PBS NA 1.2 ˜2-3Wheal at base of nipple. Easy to inject Needed to (6 Apr. 2000) Travelto some portion ice nipple and syringe of distal duct 14.8(G) PBS NA 1.4˜2-3 Wheal at base of nipple. Easy to inject. Needed to (6 Apr. 2000)Travel to some portion ice nipple and syringe. of distal duct Greensomewhat difficult to see, darker green would be better.

All publications and patent applications cited in this specification areherein incorporated by reference as if each individual publication orpatent application were specifically and individually indicated to beincorporated by reference. Although the foregoing invention has beendescribed in some detail by way of illustration and example for purposesof clarity of understanding, it will be readily apparent to those ofordinary skill in the art in light of the teachings of this inventionthat certain changes and modifications may be made thereto withoutdeparting from the spirit or scope of the appended claims.

1-22. (canceled)
 23. A method of treating a patient at risk for orhaving a precancer or cancer of a breast duct, said method comprisingthe following steps: administering to a breast duct through a ductalorifice a biocompatible composition comprising; a polymer that has asolubility greater than 0.5 grams per 100 ml of solvent, a molecularweight in a range of between about 1 and 500 kilo Daltons and aweight/weight ratio of polymer to solvent in a range of between about0.5:100 to 100:0.5, and further comprising a therapeutic additive;wherein said composition is a liquid in a solvent and undergoes a geltransition inside said breast duct within about 30 minutes ofadministration of said composition to said breast duct, and deliveringsaid therapeutic additive in said composition to precancerous orcancerous breast duct tissue and surrounding breast tissue after saidcomposition undergoes a gel transition inside said breast duct; whereinsaid therapeutic additive in said biocompatible composition that hasundergone a gel transition provides treatment of a precancer or cancerof said breast duct.
 24. A composition of claim 23, wherein the polymeris water soluble and comprises a polyethylene polypropylene glycol blockcopolymer.
 25. A composition of claim 23, wherein the solvent is water,wherein the polymer selected from the group consisting of alkylcelluloses, hydroxyalky methyl celluloses, hyaluronic acid, sodiumchondroitin sulfate, polyacrylic acid, polyacrylamide,polycyanolacrylates, methyl methacrylate polymers, 2-hydroxyethylmethacrylate polymers, cyclodextrin, polydextrose, dextran, gelatin,polygalacturonic acid, polyvinyl alcohol, polyvinyl pyrrolidone,polyalkylene glycols, and polyethylene oxide, and wherein thecomposition undergoes a gel transition between about 28° C. and 41° C.26. A biocompatible composition as in claim 23, wherein the compositionundergoes a gel transition at the physiological pH of a breast milkduct, which pH is a range of from about pH 7.5 to about pH 8.2.
 27. Acomposition as in claim 26, wherein the pH is a range of from about pH7.8 to about pH 8.2.
 28. A composition as in claim 23, wherein thepolymer is water soluble and comprises a polyethylene polypropyleneglycol block copolymer.
 29. A biocompatible composition as in claim 23,wherein the therapeutic additive is a chemotherapeutic agent or hormonemodulating agent.
 30. A composition of claim 29, wherein the therapeuticadditive is selected from the group consisting of a tamoxifen,raloxifene, EM 800, droloxifene, ioxdroxifene, RU 39411, RU 58668, ICI164384, faslodex, soy, a soy isoflavone, a gonadotropin releasinghormone agonist, or an aromatase inhibitor.
 31. A method as in claim 23,wherein the gel is selected to have a transition time from the group oftransition time ranges consisting of from about 0 to 2 minutes, fromabout 2 to 5 minutes, from about 6 to 10 minutes, from about 11 to 15minutes, from about 16 to 20 minutes, from about 21 to 25 minutes, andfrom about 26 to 30 minutes.
 32. A method as in claim 23, wherein thecomposition is administered using a catheter with a lumen small enoughto access a breast milk duct.
 33. A method as in claim 23, wherein thelumen of the portion of the catheter that access the breast ductcomprises a diameter less than 0.10 inches.
 34. A method of treating apatient at risk for or having a precancer or cancer of a breast duct,said method comprising the following steps: administering to a breastduct through a ductal orifice a composition comprising: a polymer in asolvent capable of a gel transition inside the target duct, wherein thecomposition is liquid at room temperature and undergoes a gel transitioninside the target duct within about 30 minutes of delivery of thecomposition; and further comprising a therapeutic additive; anddelivering said therapeutic additive in said composition to precancerousor cancerous breast duct tissue and surrounding breast tissue after saidcomposition undergoes a gel transition inside said breast duct; whereinsaid therapeutic additive in said biocompatible composition that hasundergone a gel transition provides treatment of a precancer or cancerof said breast duct.
 35. A composition of claim 34, wherein the polymeris water soluble and comprises a polyethylene polypropylene glycol blockcopolymer.
 36. A composition of claim 34, wherein the solvent is water,wherein the polymer selected from the group consisting of alkylcelluloses, hydroxyalky methyl celluloses, hyaluronic acid, sodiumchondroitin sulfate, polyacrylic acid, polyacrylamide,polycyanolacrylates, methyl methacrylate polymers, 2-hydroxyethylmethacrylate polymers, cyclodextrin, polydextrose, dextran, gelatin,polygalacturonic acid, polyvinyl alcohol, polyvinyl pyrrolidone,polyalkylene glycols, and polyethylene oxide, and wherein thecomposition undergoes a gel transition between about 28° C. and 41° C.37. A biocompatible composition as in claim 34, wherein the compositionundergoes a gel transition at the physiological pH of a breast milkduct, which pH is a range of from about pH 7.5 to about pH 8.2.
 38. Acomposition as in claim 37, wherein the pH is a range of from about pH7.8 to about pH 8.2.
 39. A composition as in claim 34, wherein thepolymer is water soluble and comprises a polyethylene polypropyleneglycol block copolymer.
 40. A biocompatible composition as in claim 34,wherein the therapeutic additive is a chemotherapeutic agent or hormonemodulating agent.
 41. A composition of claim 40, wherein the therapeuticadditive is selected from the group consisting of a tamoxifen,raloxifene, EM 800, droloxifene, ioxdroxifene, RU 39411, RU 58668, ICI164384, faslodex, soy, a soy isoflavone, a gonadotropin releasinghormone agonist, or an aromatase inhibitor.
 42. A method as in claim 34,wherein the gel is selected to have a transition time from the group oftransition time ranges consisting of from about 0 to 2 minutes, fromabout 2 to 5 minutes, from about 6 to 10 minutes, from about 11 to 15minutes, from about 16 to 20 minutes, from about 21 to 25 minutes, andfrom about 26 to 30 minutes.
 43. A method as in claim 34, wherein thecomposition is administered using a catheter with a lumen small enoughto access a breast milk duct.
 44. A method as in claim 34, wherein thelumen of the portion of the catheter that accesses the breast ductcomprises a diameter less than 0.10 inches.